Element.prototype.getChildNode = function () {const resArr = [];fn(this);function fn(node) {const childNodes = node.childNodes,len = childNodes.length;// 找出元素节点(node && node.nodeType === 1) && resArr.push(node);for (let i = 0; i < len; i++) {const item = childNodes[i];// 元素节点 -> 递归 -> 找下一层节点item.nodeType === 1 && fn(item);}}return resArr;}